Classpnp.sys error !Please Help!

Hi,
I am new to fourms and I would like some help. Basically I had a Windows 7 Home premium OS x64bit and it was working fine until I installed Windows 7 Ultimate on a separate partition on the same hard drive. Before i done that i changed the disk from dynamic to basic. After the installation was finished it did give me an error but I couldnt read it becuase the computer restarted. Now I have to wait 20minutes at the windows logo screen for both OS to load to desktop. When I use the safe mode it is getting stuck at Classpnp.sys for 20mins and loads. Also I am finding it hard to install my ATI display driver on the new OS as it is saying driver not supported. Any help is greatly appreciated and sorry for the long information.

Here are my specs:
Processor: Intel core i7 870 @ 2.93GHz
Memory: 6144MB RAM
VG Card: ATI Radeon HD 5570
Motherboard: ipowerG5800 [I think]

Thanks,
Harry

Hello Harry
Take a look at this thread:

http://www.sevenforums.com/crashes-debugging/141151-windows-7-safe-mode-reboots-classpnp-sys.html

Good luck